Study On The Regulation Of The Buckling Morphology Of SMP Film/Substrate Composite Column

Shape memory polymer(SMP)is a new kind of functional material.After changing its shape and fixing under certain conditions,the shape memory polymer can be stimulated by external stimuli such as light,electricity,heat and so on,so that it can be restored to the initial state in a certain way and complete the shape memory process of "deformation-memory-recovery".Because of its excellent properties such as low density,high recovery rate,good biocompatibility,wide adaptability and low cost,it is widely used in medical,manufacturing,aerospace and other fields.In practical applications,traditional SMP materials still exist such constraints as single function.In recent years,soft materials have developed rapidly.Based on the surface instability of thin film/substrate structure,an orderly buckling microstructure is formed.It has an important application prospect in the fields of biomimetic manufacturing,functional surface preparation,flexible electronic devices and so on.In this paper,a series of eperiments and finite element simulation are carried out to study the film/substrate structure system and the shape memory polymer material.The SMP material is the main material.A series of experiments and finite element simulation are carried out for the SMP film/substrate composite column.Based on the epoxy resin shape memory material,two different properties of polymer materials are used to form SMP film/substrate structure column.Thermodynamic experiments are carried out to design a specific experimental process according to the properties of the material.The processes of restoring the SMP film/substrate composite structure to the smooth surface are realized,and the multi-functions of the shape memory polymer material are achieved through the design of the film/substrate structure.The effects of pre strain and holding time on the critical buckling temperature,buckling morphology and recovery effect of SMP film/substrate structure were investigated by thermodynamic experiments.The buckling morphology of the internal and external layer film/substrate structure are discussed respectively,and two kinds of structure morphology were analyzed according to the recovery rate and stress distribution.Based on the SMP thermodynamic constitutive model and the theory of the surface instability related to the hard film/soft substrate,the influence of the structural parameters such as film thickness,substrate thickness,film/substrate modulus ratio on the buckling morphology is simulated by ABAQUS.The variation of the critical buckling wavelength with various parameters is obtained,and the simulation results are obtained.Compared with theoretical and experimental data,the goodness of fit is good.The results of this study are of great significance for the precise control of the buckling morphology of epoxy resin based SMP film/substrate composite structure.